I have read many theories on why youth culture changed forever after WWII - the growth of television, the first generation of teens to have money of their own, the ubiquity of the telephone. I had never considered that the simple increase of time spent with each other, because of the increase in the average number of years of education, might be a cause. People together naturally form ties, and bonds, and tribes, and cliques. Maybe that's all of it: human nature working as usual in a new situation.
There are flaws in the article, but I think Bauerlein basically gets it right.